Parameter | Full Cohort | P value c | Singletons Only | P value | ||
---|---|---|---|---|---|---|
ARTa (n = 8102) | SCb (n = 8096) | ART (n = 5960) | SC (n = 8005) | |||
Maternal age (years, mean (SD)) | 32.4 ± 3.6 | 32.4 ± 3.6 | 0.997 | 32.7 ± 3.7 | 32.4 ± 3.7 | < 0.001 |
Primiparous (No.(%)) | 7420(91.6) | 6013(74.3) | < 0.001 | 5734(96.2) | 6012(75.1) | < 0.001 |
Single/multiple births (No.(%)) |  |  | < 0.001 | / | / | / |
single | 5960(73.6) | 8005(98.9) | ||||
twins | 2135(26.4) | 89(1.1) | ||||
triplets | 7(0.1) | 2(0.0) | ||||
Gestational age (wk, mean (SD)) | 37.7 ± 2.1 | 38.6 ± 1.5 | < 0.001 | 38.4 ± 1.6 | 38.6 ± 1.4 | < 0.001 |
< 32 weeks (No.(%)) | 143(1.8) | 43(0.5) | < 0.001 | 52(0.9) | 36(0.4) | 0.002 |
< 37 weeks (No.(%)) | 1582(19.5) | 505(6.2) | < 0.001 | 415(7.0) | 450(5.6) | 0.001 |
Birth weight (g, mean (SD)) | 3086.3 ± 650.0 | 3306.0 ± 478.0 | < 0.001 | 3346.8 ± 497.7 | 3317.7 ± 465.4 | < 0.001 |
< 1500 g (No.(%)) | 150(1.9) | 30(0.4) | < 0.001 | 39(0.7) | 25(0.3) | 0.007 |
< 2500 g (No.(%)) | 1468(18.1) | 374(4.6) | < 0.001 | 264(4.4) | 312(3.9) | < 0.001 |
≥4000 g (No.(%)) | 445(5.5) | 501(6.2) | 0.071 | 445(7.5) | 499(6.2) | 0.010 |
Obstetrical events (No.(%)) | ||||||
 Cesarean section | 6183(76.3) | 4093(50.6) | < 0.001 | 4118(69.1) | 4005(50.0) | < 0.001 |
 Placenta previa | 558(6.9) | 161(2.0) | < 0.001 | 368(6.2) | 159(2.0) | < 0.001 |
 Hypertensive disorders | 1017(12.6) | 763(9.4) | < 0.001 | 578(9.7) | 744(9.3) | 0.420 |
 Gestational Diabetes | 1806(22.3) | 1412(17.4) | < 0.001 | 1303(21.9) | 1389(17.4) | < 0.001 |